The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri
A method for the determination of integrated longitudinal stellar fields from low-resolution spectra is the so-called slope method, which is based on the regression of the Stokes V signal against the first derivative of Stokes I. Here we investigate the possibility to extend this technique to measur...
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ftdatacite:10.48550/arxiv.1708.05196 2023-05-15T18:50:47+02:00 The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri Scalia, C. Leone, F. Gangi, M. Giarrusso, M. Stift, M. J. 2017 https://dx.doi.org/10.48550/arxiv.1708.05196 https://arxiv.org/abs/1708.05196 unknown arXiv https://dx.doi.org/10.1093/mnras/stx2090 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences article-journal Article ScholarlyArticle Text 2017 ftdatacite https://doi.org/10.48550/arxiv.1708.05196 https://doi.org/10.1093/mnras/stx2090 2022-04-01T10:26:37Z A method for the determination of integrated longitudinal stellar fields from low-resolution spectra is the so-called slope method, which is based on the regression of the Stokes V signal against the first derivative of Stokes I. Here we investigate the possibility to extend this technique to measure the magnetic fields of cool stars from high resolution spectra. For this purpose we developed a multi-line modification to the slope method, called multi-line slope method. We tested this technique by analysing synthetic spectra computed with the COSSAM code and real observations obtained with the high resolution spectropolarimeters Narval, HARPSpol and Catania Astrophysical Observatory Spectropolarimeter (CAOS). We show that the multi-line slope method is a fast alternative to the Least Squares Deconvolution (LSD) technique for the measurement of the effective magnetic fields of cool stars. Using a Fourier transform on the effective magnetic field variations of the star $ε$ Eri, we find that the long term periodicity of the field corresponds to the 2.95 yr period of the stellar dynamo, revealed by the variation of the activity index. : 11 pages, 8 figures, 6 tables Text narval narval DataCite Metadata Store (German National Library of Science and Technology) |
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Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences |
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Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences Scalia, C. Leone, F. Gangi, M. Giarrusso, M. Stift, M. J. The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
topic_facet |
Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences |
description |
A method for the determination of integrated longitudinal stellar fields from low-resolution spectra is the so-called slope method, which is based on the regression of the Stokes V signal against the first derivative of Stokes I. Here we investigate the possibility to extend this technique to measure the magnetic fields of cool stars from high resolution spectra. For this purpose we developed a multi-line modification to the slope method, called multi-line slope method. We tested this technique by analysing synthetic spectra computed with the COSSAM code and real observations obtained with the high resolution spectropolarimeters Narval, HARPSpol and Catania Astrophysical Observatory Spectropolarimeter (CAOS). We show that the multi-line slope method is a fast alternative to the Least Squares Deconvolution (LSD) technique for the measurement of the effective magnetic fields of cool stars. Using a Fourier transform on the effective magnetic field variations of the star $ε$ Eri, we find that the long term periodicity of the field corresponds to the 2.95 yr period of the stellar dynamo, revealed by the variation of the activity index. : 11 pages, 8 figures, 6 tables |
format |
Text |
author |
Scalia, C. Leone, F. Gangi, M. Giarrusso, M. Stift, M. J. |
author_facet |
Scalia, C. Leone, F. Gangi, M. Giarrusso, M. Stift, M. J. |
author_sort |
Scalia, C. |
title |
The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
title_short |
The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
title_full |
The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
title_fullStr |
The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
title_full_unstemmed |
The multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε Eri |
title_sort |
multi-line slope method for the measure of the effective magnetic field of the cool stars: an application to the solar like cycle of ε eri |
publisher |
arXiv |
publishDate |
2017 |
url |
https://dx.doi.org/10.48550/arxiv.1708.05196 https://arxiv.org/abs/1708.05196 |
genre |
narval narval |
genre_facet |
narval narval |
op_relation |
https://dx.doi.org/10.1093/mnras/stx2090 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1708.05196 https://doi.org/10.1093/mnras/stx2090 |
_version_ |
1766244533176107008 |